WO2013008876A1 - Composite substrate - Google Patents

Abstract

This composite substrate, in which a glass plate and a resin plate are bonded together, is characterized in that the refractive index (nd) of the glass plate is 1.55 to 2.3 and the refractive index (nd) of the resin plate is 1.55 to 2.3.

Description

Composite board

The present invention relates to a composite substrate obtained by bonding a high refractive index glass plate and a high refractive index resin plate, for example, an organic EL device, particularly a composite substrate suitable for organic EL lighting.

In recent years, displays and lighting using organic EL light emitting elements have been attracting more and more attention. These organic EL devices have a structure in which an organic light emitting element is sandwiched between substrates on which a transparent conductive film such as ITO is formed. In this structure, when a current flows through the organic light emitting device, holes and electrons in the organic light emitting device associate to emit light. The emitted light enters the substrate through a transparent conductive film such as ITO, and is emitted to the outside while being repeatedly reflected in the substrate.

By the way, the refractive index nd of the organic light emitting device is 1.9 to 2.1, and the refractive index nd of ITO is 1.9 to 2.0. On the other hand, the refractive index nd of the substrate is usually about 1.5. For this reason, the conventional organic EL device has a problem that the reflectance is high due to the difference in refractive index at the substrate-ITO interface, and the light generated from the organic light emitting element cannot be extracted efficiently.

On the other hand, when a glass substrate having a high refractive index is used to extract light from the organic light emitting device, the reflectance at the substrate-air interface increases, and there is a problem that light cannot be extracted efficiently.

Therefore, it is a technical object of the present invention to provide a substrate with high light extraction efficiency.

As a result of intensive studies, the present inventors have found that the above technical problem can be solved by regulating the refractive indexes of the glass plate and the resin plate within a predetermined range and further bonding them together. As suggested. That is, the composite substrate of the present invention is a composite substrate in which a glass plate and a resin plate are bonded together, the refractive index nd of the glass plate is 1.55 or more and 2.3 or less, and the refractive index nd of the resin plate is It is 1.55 or more and 2.3 or less. Here, the purpose of bonding the resin plate to the glass plate is to suppress the light emitted from the organic layer due to the difference in refractive index between the organic layer, the glass plate and the resin plate, and to improve the efficiency. This is to prevent scattering when the glass plate is broken.

In this way, it is possible to reduce the reflectance at the substrate-air interface while reducing the reflectance at the substrate-ITO interface. In the case of a resin plate, it is easy to form a non-reflective structure on the surface, and if the surface is in contact with the air such as organic EL lighting, the light generated in the organic light emitting layer is difficult to return into the organic light emitting layer. As a result, the light extraction efficiency can be increased.

Here, the “refractive index nd of the glass plate” can be measured with a refractive index measuring device. For example, after preparing a rectangular parallelepiped sample of 25 mm × 25 mm × about 3 mm, (Ta + 30 ° C.) to (strain point−50 ° C.) Refractive index measuring instrument KPR manufactured by Shimadzu Corporation while annealing between the glass and the prism is performed by annealing at a cooling rate such that the temperature range is 0.1 ° C./min. It can be measured by using -2000. Further, the “refractive index nd of the resin plate” can be measured with a refractive index measuring instrument, for example, with an eprisometer.

Second, in the composite substrate of the present invention, the glass plate has a glass composition of mol%, SiO ₂ 10-70%, B ₂ O ₃ 0-10%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 0.1 -60%, La ₂ O ₃ 0-35%, Li ₂ O + Na ₂ O + K ₂ O 0-15%, molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 0 It is preferable that the strain point is 600 ° C. or higher and the refractive index nd is 1.55 to 2.3. Here, “SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ ” refers to the total amount of SrO, BaO, La ₂ O ₃ , and Nb ₂ O ₅ . “Li ₂ O + Na ₂ O + K ₂ O” refers to the total amount of Li ₂ O, Na ₂ O, and K ₂ O. “MgO + CaO + SrO + BaO” refers to the total amount of MgO, CaO, SrO, and BaO. “La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ” refers to the total amount of La ₂ O ₃ , Nb ₂ O ₅ , BaO, TiO ₂ , and ZrO ₂ . “Strain point” refers to a value measured based on the method described in ASTM C336-71.

Thirdly, in the composite substrate of the present invention, the glass plate is preferably made of glass having a liquidus temperature of 1250 ° C. or lower. Here, the “liquid phase temperature” is obtained by passing the standard sieve 30 mesh (500 μm) and putting the glass powder remaining on 50 mesh (300 μm) into a platinum boat and holding it in a temperature gradient furnace for 24 hours to precipitate crystals. Refers to the value of the measured temperature.

Fourthly, in the composite substrate of the present invention, the glass plate is preferably made of glass having a liquidus viscosity of 10 ^3.5 dPa · s or more. Here, “liquid phase viscosity” refers to a value obtained by measuring the viscosity of glass at the liquid phase temperature by a platinum ball pulling method.

Fifth, it is preferable that the composite substrate of the present invention is formed by molding a glass plate by an overflow down draw method. Here, the “overflow down-draw method” is a method in which molten glass is overflowed from both sides of a heat-resistant bowl-shaped structure, and the molten glass overflowed is joined at the lower end of the bowl-like structure and stretched downward. This is a method of forming a glass plate.

Sixth, in the composite substrate of the present invention, it is preferable that the surface roughness Ra of at least one surface (particularly the effective surface) of the glass plate is 10 nm or less. In the case of an organic EL lighting device, ITO is usually formed on one surface of a glass plate. When the smoothness of the surface on which ITO is formed is low, uneven brightness tends to occur in the organic EL lighting device. Therefore, if the surface roughness Ra of at least one surface (particularly the effective surface) of the glass plate is set to 10 nm or less and ITO is formed on the surface, it becomes easy to prevent such a problem. Here, “surface roughness Ra” refers to a value measured by a method based on JIS B0601: 2001.

Seventh, the composite substrate of the present invention preferably has a glass plate thickness of 2.0 mm or less.

Eighth, in the composite substrate of the present invention, the glass plate is preferably made of glass having a density of 4.0 g / cm ³ or less.

Ninthly, in the composite substrate of the present invention, the glass plate preferably has a width of 100 mm or more and a length of 100 mm or more.

Tenth, in the composite substrate of the present invention, the resin plate is made of any one of polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylonitrile copolymer, polyester, polyamide, polyimide, polyurethane, epoxy resin, polycarbonate, and acrylic. It is preferable to become.

Eleventh, the composite substrate of the present invention preferably has a concavo-convex structure formed on at least one surface of the resin plate. By doing so, the uneven structure on the surface of the resin plate suppresses the reflection on the substrate surface, so that the light extraction efficiency can be increased. Here, it may be possible to form a concavo-convex structure on the surface of the glass plate by sandblasting or the like, but in this case, the strength of the glass plate is lowered and it is difficult to form an ideal concavo-convex configuration. There is a drawback. Therefore, it is preferable to form an uneven structure on the surface of the resin plate as described above.

Twelfth, in the composite substrate of the present invention, the surface roughness Ra of at least one surface (particularly the effective surface) of the resin plate is preferably 0.5 nm or more.

Thirteenth, the composite substrate of the present invention preferably has a resin plate thickness of 0.01 to 3 mm.

Fourteenth, the composite substrate of the present invention preferably has an adhesive layer between the glass plate and the resin plate, and the thickness of the adhesive layer is preferably 100 μm or less.

Fifteenth, the composite substrate of the present invention preferably has a value of (refractive index nd of resin plate) − (refractive index nd of glass plate) of 0.001 to 0.1.

Sixteenth, the composite substrate of the present invention preferably has a haze value of 5% or more. Here, the “haze value” is a value measured based on JIS K7361-1 (1997), and can be measured by, for example, a commercially available haze meter.

Seventeenth, the composite substrate of the present invention is preferably used for a lighting device.

Eighteenth, the composite substrate of the present invention is preferably used for organic EL lighting.

Nineteenth, the composite substrate of the present invention is preferably used for an organic EL display.

According to the present invention, since the refractive indexes of the glass plate and the resin plate included in the composite substrate are appropriately regulated, reflection that adversely affects light extraction is suppressed, and light extraction efficiency is improved. Is possible.

The composite substrate according to an embodiment of the present invention is obtained by bonding a resin plate to one side of a glass plate, and is used for, for example, an organic EL display or organic EL lighting. Hereinafter, the glass plate and the resin plate included in the composite substrate according to the present embodiment will be described in detail. In the following embodiments, a composite resin plate in which a resin plate is bonded to one side of a glass plate will be described. However, the composite resin plate of the present invention is a composite resin plate in which a resin plate is bonded to both sides of a glass plate. It may be.

The refractive index nd of the glass plate included in the composite substrate according to the present embodiment is 1.55 or more, preferably 1.58 or more, 1.60 or more, 1.63 or more, particularly 1.64 or more. When the refractive index nd of the glass plate is less than 1.55, light cannot be efficiently extracted outside due to reflection at the ITO-glass interface. On the other hand, if the refractive index nd of the glass plate is too high, the reflectance at the interface between the glass plate and the resin plate increases, and the light extraction efficiency tends to decrease. Therefore, the refractive index nd of the glass plate is preferably 2.30 or less, 2.00 or less, 1.90 or less, 1.85 or less, 1.80 or less, 1.75 or less, particularly 1.70 or less.

The above glass plate desirably has the following glass composition, glass characteristics, and the like. In addition, in description of the containing range of each component,% display represents mol% unless there is particular notice.

The content of SiO ₂ is preferably 10 to 70%. When the content of SiO ₂ decreases, it becomes difficult to form a glass network structure, and vitrification becomes difficult. Further, the viscosity of the glass is excessively lowered, and it becomes difficult to ensure a high liquid phase viscosity. Therefore, the content of SiO ₂ is preferably 15% or more, 20% or more, 30% or more, 40% or more, 45% or more, 50% or more, particularly 55% or more. On the other hand, when the content of SiO ₂ increases, the meltability and moldability tend to decrease, and the refractive index nd tends to decrease. Therefore, the content of SiO ₂ is preferably 68% or less, 65% or less, particularly 63% or less.

The content of Al ₂ O ₃ is preferably 0 to 20%. When the content of Al ₂ O ₃ is increased, devitrified crystals are likely to be precipitated on the glass, and the liquid phase viscosity is likely to be lowered. Further, the refractive index nd tends to decrease. Therefore, the content of Al ₂ O ₃ is preferably 15% or less, 10% or less, 8% or less, and particularly preferably 6% or less. Incidentally, the content of Al ₂ O ₃ is reduced, lacks component balance of the glass composition, the glass is liable to devitrify reversed. Therefore, the content of Al ₂ O ₃ is preferably 0.1% or more, 0.5% or more, and particularly preferably 1% or more.

When the content of B ₂ O ₃ increases, the refractive index nd and Young's modulus tend to decrease, and the strain point tends to decrease. Therefore, the content of B ₂ O ₃ is preferably 10% or less, 8% or less, and particularly preferably 6% or less. On the other hand, when the content of B ₂ O ₃ is reduced, the devitrification resistance is likely to be lowered. Therefore, the content of B ₂ O ₃ is preferably 0.1% or more, particularly preferably 1% or more.

SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ is a component that increases the refractive index nd without impairing devitrification resistance. However, if added in a large amount, the component balance of the glass composition is lost, and conversely, the devitrification resistance tends to be lowered, and the density and the thermal expansion coefficient may be too high. A preferable lower limit range of SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ is 0.1% or more, 5% or more, 10% or more, 15% or more, particularly 18% or more. Moreover, the suitable upper limit of SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ is 60% or less, 50% or less, 40% or less, 35% or less, 25% or less, particularly 22% or less.

The SrO content is preferably 0 to 20%. When the SrO content increases, the refractive index nd, density, and thermal expansion coefficient tend to increase. When the SrO content is excessive, the glass composition component balance is lost and the devitrification resistance tends to decrease. Therefore, the content of SrO is preferably 18% or less, 14% or less, 12% or less, 11% or less, 8% or less, 7% or less, particularly 6% or less. Note that when the content of SrO decreases, the meltability tends to decrease, and the refractive index nd tends to decrease. Therefore, the content of SrO is preferably 0.1% or more, 0.8% or more, 1.4% or more, 3% or more, particularly 4% or more.

The content of BaO is preferably 0 to 60%. BaO is a component that increases the refractive index nd without drastically reducing the viscosity among alkaline earth metal oxides. When the content of BaO increases, the refractive index nd, density, and thermal expansion coefficient tend to increase. However, when there is too much content of BaO, the component balance of a glass composition will be missing and devitrification resistance will fall easily. Therefore, the BaO content is preferably 50% or less, 45% or less, 40% or less, 35% or less, 34% or less, 32% or less, and particularly preferably 30% or less. In addition, when content of BaO decreases, in addition to becoming difficult to obtain desired refractive index nd, it becomes difficult to ensure a high liquid phase viscosity. Therefore, the content of BaO is preferably 0.1% or more, 1% or more, 2% or more, 5% or more, 10% or more, particularly 13% or more.

La ₂ O ₃ is a component that increases the refractive index nd. When the content of La ₂ O ₃ increases, the density and thermal expansion coefficient become too high, and devitrification resistance tends to decrease. Therefore, a suitable upper limit range of La ₂ O ₃ is 35% or less, 25% or less, 15% or less, 10% or less, 8% or less, 5% or less, particularly 3% or less. In the case of adding _La 2 _{O 3,} the amount added is less than 0.1%, 0.3% or more, 0.5% or more, 0.8% or more, particularly 1% or more is preferable.

Nb ₂ O ₅ is a component that increases the refractive index nd. When the content of Nb ₂ O ₅ increases, the density and the thermal expansion coefficient become too high, and the devitrification resistance tends to decrease. Therefore, the content of Nb ₂ O ₅ is 0 to 10%, 0 to 7%, 0 to 5%, 0 to 3%, 0 to 1%, 0 to 0.5%, particularly 0 to 0.1%. preferable.

The molar ratio (MgO + CaO) / (SrO + BaO) is preferably 0 to 1. If the molar ratio (MgO + CaO) / (SrO + BaO) is too large, the balance of the glass composition is lost, and conversely, the devitrification resistance is liable to be lowered. It becomes easy to do. On the other hand, if the molar ratio (MgO + CaO) / (SrO + BaO) is too small, the density may be too high. Therefore, a preferable lower limit range of the molar ratio (MgO + CaO) / (SrO + BaO) is 0.1 or more, 0.2 or more, 0.3 or more, particularly 0.35 or more. Moreover, the suitable upper limit of molar ratio (MgO + CaO) / (SrO + BaO) is 0.8 or less, 0.7 or less, 0.6 or less, and especially 0.5 or less. Here, “MgO + CaO” is the total amount of MgO and CaO. “SrO + BaO” is the total amount of SrO and BaO.

MgO is a component that increases the refractive index nd, Young's modulus, and strain point, and also decreases the high-temperature viscosity. However, when a large amount of MgO is added, the liquidus temperature increases and the devitrification resistance decreases. Or the density and thermal expansion coefficient may become too high. Therefore, the content of MgO is preferably 20% or less, 15% or less, 10% or less, 5% or less, 3% or less, and particularly preferably 1% or less.

The CaO content is preferably 0 to 15%. When the content of CaO increases, the density and the thermal expansion coefficient tend to increase. When the content is too large, the balance of the glass composition is lost and the devitrification resistance tends to decrease. Therefore, the CaO content is preferably 15% or less, 13% or less, 11% or less, and particularly preferably 9.5% or less. Note that when the content of CaO decreases, the meltability decreases, the Young's modulus decreases, and the refractive index nd tends to decrease. Therefore, the CaO content is preferably 0.5% or more, 1% or more, 2% or more, 4% or more, 6% or more, particularly 7% or more.

The molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is preferably 0.1 to 4. If the molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is too large, the refractive index nd tends to decrease. However, if the molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is too small, it is difficult to obtain a high liquid phase viscosity, and the density and thermal expansion coefficient may be too high. . Therefore, a preferable lower limit range of the molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 0.1 or more, 0.3 or more, 0.5 or more, 0.8 or more, 1 or more. 1.3 or more, particularly 1.5 or more. The preferred upper limit range of the molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 4 or less, 3.5 or less, 3 or less, 2.8 or less, 2.5 or less, particularly 2 0.0 or less.

TiO ₂ is a component that increases the refractive index nd. When the content of TiO ₂ increases, the devitrification resistance tends to decrease. Therefore, the content of TiO ₂ is preferably 0 to 20%, 0 to 15%, 0 to 10%, 0 to 8%, 0 to 6%, particularly preferably 0 to 5%.

ZrO ₂ is a component that increases the refractive index nd. When the content of ZrO ₂ increases, the devitrification resistance tends to decrease. Therefore, the content of ZrO ₂ is preferably 0 to 20%, 0 to 15%, 0 to 10%, 0 to 8%, 0 to 6%, particularly preferably 0 to 5%.

Li ₂ O + Na ₂ O + K ₂ O is a component that lowers the viscosity and adjusts the coefficient of thermal expansion. However, when added in a large amount, the viscosity decreases too much and it is difficult to ensure a high liquid phase viscosity. . Therefore, the content of Li ₂ O + Na ₂ O + K ₂ O is preferably 10% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.5% or less, and particularly preferably 0.1% or less. The contents of Li ₂ O, Na ₂ O and K ₂ O are each preferably 8% or less, 5% or less, 2% or less, 1% or less, 0.5% or less, particularly preferably 0.1% or less.

As a fining agent, one or two or more selected from the group of As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ , SnO ₂ , F, Cl, and SO ₃ are used in an amount of 0 to 3%, particularly 0.1 to 2%. It may be added. However, As ₂ O ₃ , Sb ₂ O ₃ , and F, particularly As ₂ O ₃ and Sb ₂ O ₃ , it is preferable to refrain from using them as much as possible from an environmental point of view. % Is preferred. From an environmental point of view, SnO ₂ , SO ₃ , and Cl are preferable as the fining agent. In particular, the SnO ₂ content is preferably 0 to 3%, 0 to 1%, 0.01 to 0.5%, particularly 0.05 to 0.4%. Further, the content of SnO ₂ + SO ₃ + Cl is preferably 0 to 3%, 0 to 1%, 0.001 to 1%, 0.01 to 0.5%, and particularly preferably 0.01 to 0.3%. Here, “SnO ₂ + SO ₃ + Cl” refers to the total amount of SnO ₂ , SO ₃ , and Cl.

PbO is a component that lowers the viscosity at high temperature and increases the refractive index, but from an environmental point of view, it is preferable to refrain from using it as much as possible, and its content is preferably 0.5% or less, and is not substantially contained. It is desirable. Here, “substantially does not contain PbO” refers to a case where the content of PbO in the glass composition is less than 1000 ppm (mass).

Other than the above components, other components may be added up to 15%, for example.

It is possible to produce a suitable glass plate by combining a suitable content range and glass characteristics of each component. Among them, particularly suitable glass composition ranges and combinations of glass characteristics are as follows.

(1) As a glass composition, mol%, SiO ₂ 20-70%, B ₂ O ₃ 0-8%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 5-50%, La ₂ O ₃ 0.1-30% , Li ₂ O + Na ₂ O + K ₂ O 0 to 5%, (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) in a molar ratio of 0.5 to 3.5, and refractive index nd is 1.55 to 2.00.

(2) As glass composition, mol ₂ %, SiO ₂ 40-70%, B ₂ O ₃ 0-5%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 10-40%, La ₂ O ₃ 0.3-15% , Li ₂ O + Na ₂ O + K ₂ O 0 to 3%, (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) in a molar ratio of 1 to 3.5, and refractive index nd 1.55-1.85.

(3) As a glass composition, mol%, SiO ₂ 50 to 70%, B ₂ O ₃ 0 to 3%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 15 to 35%, La ₂ O ₃ 0.5 to 10% , Li ₂ O + Na ₂ O + K ₂ O 0 to 1%, the molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 1.3 to 3, and the refractive index nd is 1 .55 to 1.80.

(4) As a glass composition, mol%, SiO ₂ 50 to 70%, B ₂ O ₃ 0 to 1%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 15 to 25%, La ₂ O ₃ 0.8 to 5% , Li ₂ O + Na ₂ O + K ₂ O 0 to 0.5%, molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 1.5 to 2.5, and refraction The rate nd is 1.55 to 1.80.

(5) Glass composition is mol%, SiO ₂ 50-70%, B ₂ O ₃ 0-0.1%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 18-22%, La ₂ O ₃ 1-3% , Li ₂ O + Na ₂ O + K ₂ O 0 to 0.1%, molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 1.5 to 2.5, and refraction The rate nd is 1.60 to 1.70.

(6) As glass composition, mol%, SiO ₂ 50-70%, B ₂ O ₃ 0-8%, MgO 5-15%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 18-22%, La ₂ O ₃ 0 to 3%, Li ₂ O + Na ₂ O + K ₂ O 0 to 0.1%, molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 1.5 to 2.0 And the refractive index nd is 1.62 to 1.68.

The density of the glass plate is preferably 4.0 g / cm ³ or less, 3.7 g / cm ³ or less, 3.5 g / cm ³ or less, particularly 3.4 g / cm ³ or less. In this way, the device can be reduced in weight.

In the above glass plate, the thermal expansion coefficient at 30 to 380 ° C. is 45 × 10 ⁻⁷ to 110 × 10 ⁻⁷ / ° C., 50 × 10 ⁻⁷ to 100 × 10 ⁻⁷ / ° C., 60 × 10 ⁻⁷ to 95 × 10 ⁻⁷ / ° C., 65 × 10 ⁻⁷ to 90 × 10 ⁻⁷ / ° C., 65 × 10 ⁻⁷ to 85 × 10 ⁻⁷ / ° C., especially 70 × 10 ⁻⁷ to 80 × 10 ⁻⁷ / ° C. Is preferred. If the thermal expansion coefficient is too low, the thermal expansion coefficients of the organic EL thin film and the transparent conductive film are not matched, and the glass plate may be warped. On the other hand, when the thermal expansion coefficient is too high, when a glass frit is used to laser-seal an organic EL device, the glass plate is easily broken by thermal shock. Therefore, if the thermal expansion coefficient is regulated within the above range, such a situation can be easily prevented.

The strain point of the glass plate is preferably 630 ° C. or higher, 650 ° C. or higher, 670 ° C. or higher, 690 ° C. or higher, particularly 700 ° C. or higher. When laser sealing an organic EL lighting device or the like using a glass frit, if the heat resistance of the glass plate is low, the glass plate is likely to crack.

In the above glass plate, the temperature at 10 ^2.5 dPa · s is preferably 1450 ° C. or lower, 1400 ° C. or lower, 1370 ° C. or lower, 1330 ° C. or lower, particularly 1290 ° C. or lower. If it does in this way, since meltability will improve, the manufacturing efficiency of a glass plate will improve.

The liquidus temperature of the glass plate is preferably 1250 ° C. or lower, 1150 ° C. or lower, 1130 ° C. or lower, 1110 ° C. or lower, 1090 ° C. or lower, 1050 ° C. or lower, 1030 ° C. or lower, particularly 1000 ° C. or lower. The liquid phase viscosity is 10 ^3.5 dPa · s or more, 10 ^3.8 dPa · s or more, 10 ^4.2 dPa · s or more, 10 ^4.4 dPa · s or more, 10 ^4.6 dPa · s or more. It is preferably 10 ^5.0 dPa · s or more, particularly preferably 10 ^5.2 dPa · s or more. If it does in this way, it will become difficult to devitrify glass at the time of shaping | molding, and it will become easy to shape | mold a glass plate by the overflow down draw method.

The thickness of the glass plate is 2.0 mm or less, 1.5 mm or less, 1.3 mm or less, 1.1 mm or less, 0.8 mm or less, 0.6 mm or less, 0.5 mm or less, 0.3 mm or less, 0 .2 mm or less, particularly 0.1 mm or less is preferable. As the plate thickness of the glass plate is smaller, the flexibility of the glass plate is increased, and it becomes easier to produce a lighting device with high design. However, when the plate thickness of the glass plate is extremely small, the glass plate is easily damaged. Therefore, the thickness of the glass plate is preferably 10 μm or more, particularly preferably 30 μm or more.

The width of the glass plate is preferably 5 mm or more, 10 mm or more, 50 mm or more, 100 mm or more, 300 mm or more, particularly 500 mm or more. The length of the glass plate is preferably 5 mm or more, 10 mm or more, 50 mm or more, 100 mm or more, 300 mm or more, particularly 500 mm or more. In this way, it becomes easy to increase the size of the organic EL lighting or the like.

It is preferable that at least one surface (preferably both surfaces) of the glass plate is unpolished. Although the theoretical strength of glass is very high, it often breaks at a stress much lower than the theoretical strength. This is because a small defect called Griffith flow occurs on the glass surface in a post-molding process such as a polishing process. Therefore, if the glass surface is unpolished, the original mechanical strength of the glass is hardly lost, and the glass plate is difficult to break. Further, if the surface of the glass plate is unpolished, the polishing step can be omitted, and the manufacturing cost of the glass plate can be reduced.

In the glass plate, the surface roughness Ra of at least one surface (preferably both surfaces) is preferably 10 nm or less, 5 nm or less, 1 nm or less, 0.5 nm or less, 0.3 nm or less, particularly preferably 0.2 nm or less. When the surface roughness Ra is larger than 10 nm, when ITO is formed on the surface, the quality of the ITO is lowered and it becomes difficult to obtain uniform light emission.

The above glass plate is preferably formed by an overflow down draw method. In this way, it is possible to produce a glass plate that is unpolished and has good surface quality. The reason is that, in the case of the overflow down draw method, the surface to be the surface is not in contact with the bowl-shaped refractory and is molded in a free surface state. The structure and material of the bowl-shaped structure are not particularly limited as long as desired dimensions and surface accuracy can be realized. Further, there is no particular limitation on the method for applying force to the molten glass in order to perform downward stretching. For example, a method may be adopted in which a heat-resistant roll having a sufficiently large width is rotated and stretched in contact with the molten glass, and a plurality of pairs of heat-resistant rolls are provided only in the vicinity of the end surface of the molten glass. You may employ | adopt the method of making it contact and extending | stretching.

In addition to the overflow downdraw method, for example, a downdraw method (slot down method, redraw method, etc.), a float method, a rollout method, etc. can be employed.

The above glass plate is manufactured, for example, as follows. That is, first, glass raw materials are prepared so as to obtain a desired glass composition, and a glass batch is produced. Next, the glass batch is melted and refined, and then formed into a desired shape. Thereafter, it is processed into a desired shape.

The refractive index nd of the resin plate included in the composite substrate according to the present embodiment is 1.55 or more, preferably 1.58 or more, 1.60 or more, 1.63 or more, particularly 1.64 or more. When the refractive index nd of the resin plate is less than 1.55, it is difficult to increase the light extraction efficiency of the organic EL illumination. On the other hand, if the refractive index nd of the resin plate is too high, the transmittance of the resin plate is reduced or it is difficult to mold into a plate shape. Therefore, the refractive index nd of the resin plate is preferably 2.3 or less, 2.0 or less, 1.9 or less, 1.8 or less, 1.75 or less, particularly 1.7 or less.

From the viewpoint of production cost, the material of the above resin plate is one of polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylonitrile copolymer, polyester, polyamide, polyimide, polyurethane, epoxy resin, polycarbonate, and acrylic. Is preferred.

The thickness of the resin plate is 2.0 mm or less, 1.5 mm or less, 1.3 mm or less, 1.1 mm or less, 0.8 mm or less, 0.6 mm or less, 0.5 mm or less, 0.3 mm or less, 0. 2 mm or less, especially 0.1 mm or less are preferable. The smaller the thickness of the resin plate, the higher the flexibility of the resin plate and the easier it is to produce a lighting device with high design. However, when the thickness of the resin plate becomes extremely small, the resin plate is easily damaged. Therefore, the thickness of the resin plate is preferably 10 μm or more, particularly preferably 30 μm or more.

The surface roughness Ra of at least one surface of the resin plate is preferably 10 nm or less, 5 nm or less, 1 nm or less, 0.5 nm or less, 0.3 nm or less, and particularly preferably 0.2 nm or less. When the surface roughness Ra is larger than 10 nm, it becomes difficult to control the film thickness of the transparent conductive film or the organic layer formed on the glass substrate. In addition, when bonding to the glass plate, bubbles may be taken into the interface and the appearance quality may be reduced.

The above resin plate preferably has a concavo-convex structure, particularly a square pyramid, formed on at least one surface in order to increase light extraction efficiency. For the concavo-convex structure, the period, depth, shape, etc. of the concavo-convex structure may be determined in consideration of the refractive index nd of the glass plate, the thickness of the organic material, the refractive index nd of the resin plate, and the like.

In the composite substrate according to this embodiment, the values of (refractive index nd of resin plate) − (refractive index nd of glass plate) are 0.001 to 0.1, 0.001 to 0.05, 0.001 to 0. 0.03, 0.001 to 0.01, 0.001 to 0.0008, and particularly 0.001 to 0.0005 are preferred. When the value of (refractive index nd of the resin plate) − (refractive index nd of the glass plate) is less than 0.001, the reflectance at the glass plate-resin plate interface increases, and the light extraction efficiency tends to decrease. . On the other hand, if the value of (refractive index nd of the resin plate) − (refractive index nd of the glass plate) is too large, the reflection loss at the resin plate-air interface increases, and the light extraction efficiency tends to decrease.

In the composite substrate according to this embodiment, an adhesive may be used to bond the glass plate and the resin plate. When the adhesive is used, it is preferable to use EVA (ethylene-vinyl acetate copolymer resin), ultraviolet effect resin, thermosetting resin, OCA (Optical Clear Adhesive highly transparent adhesive transfer tape), or the like.

The thickness of the adhesive layer is preferably 100 μm or less, 80 μm or less, 50 μm or less, 30 μm or less, 10 μm or less, 8 μm or less, 5 μm or less, particularly 3 μm or less. In this way, since the thickness of the composite substrate is reduced, the device can be easily reduced in weight and thickness.

In the composite substrate according to this embodiment, the haze value is preferably 5% or more, 10% or more, 30% or more, 50% or more, 70% or more, 80% or more, 90% or more, 93% or more, particularly 98% or more. . By doing so, the reflectance at the resin plate-air interface is lowered, so that the light extraction efficiency can be increased.

Examples of the present invention will be described based on examples. In addition, an Example is a mere illustration and this invention is not limited to the following Examples at all.

Tables 1 to 3 show examples of the present invention (sample Nos. 1 to 14). In the table, PET refers to polyethylene terephthalate, and PEN refers to polyethylene naphthalate.

First, after preparing glass raw materials so as to have the glass compositions shown in Tables 1 to 3, the obtained glass batch was supplied to a glass melting furnace and melted at 1500 to 1600 ° C. for 4 hours. Next, after the obtained molten glass was poured out on a carbon plate and formed into a plate shape, a predetermined annealing treatment was performed. Subsequently, polishing treatment was performed until the plate thickness described in the table was reached. Finally, various characteristics of the obtained glass plate were evaluated.

The density ρ is a value measured by the well-known Archimedes method.

The thermal expansion coefficient α is a value obtained by measuring an average value at 30 to 380 ° C. using a dilatometer. As a measurement sample, a cylindrical sample having a diameter of 5 mm × 20 mm (the end surface is R-processed) was used.

The strain point Ps is a value measured based on the method described in ASTM C336-71. In addition, heat resistance becomes high, so that the strain point Ps is high.

The softening point Ta and the softening point Ts are values measured based on the method described in ASTM C338-93.

The temperatures at high temperature viscosities of 10 ^4.0 dPa · s, 10 ^3.0 dPa · s, 10 ^2.5 dPa · s, and 10 ^2.0 dPa · s are values measured by the platinum ball pulling method. In addition, it is excellent in meltability, so that these temperatures are low.

The liquid phase temperature TL passes through a standard sieve 30 mesh (500 μm), and the glass powder remaining in 50 mesh (300 μm) is placed in a platinum boat and held in a temperature gradient furnace for 24 hours to measure the temperature at which crystals precipitate. It is the value. Further, the liquidus viscosity log ₁₀ ηTL indicates a value obtained by measuring the viscosity of the glass at the liquidus temperature TL by a platinum ball pulling method. Note that the higher the liquidus viscosity log ₁₀ ηTL and the lower the liquidus temperature TL, the better the devitrification resistance and the moldability.

Refractive indexes nd and nC of the glass plate are first a rectangular parallelepiped sample of 25 mm × 25 mm × about 3 mm, and then the temperature range from (Ta + 30 ° C.) to (strain point−50 ° C.) is 0.1 ° C./min. It is a value measured by using a refractive index measuring instrument KPR-2000 manufactured by Shimadzu Corporation while annealing with a cooling rate as described above and then infiltrating an immersion liquid having a matching refractive index between the glasses. Further, the refractive indexes nd and nC of the resin plate are values measured by an eprisometer.

Using OCA (thickness: 175 μm), the above glass plate and the resin plate described in the table were bonded together with a laminator to prepare a composite substrate.

Sample No. listed in Table 3 With respect to the composite substrates 11 to 14, the haze value was measured with a double beam haze meter. 11 is 88%, sample no. 12 is 95%, sample no. 13 is 82%, sample no. 14 was 74%.

Sample No. listed in Table 1 After preparing glass raw materials so that the glass compositions described in 5 and 11 were obtained, the obtained glass batch was put into a continuous kiln and melted at a temperature of 1450 to 1600 ° C. Subsequently, the obtained molten glass was molded by an overflow down draw method to obtain a glass plate having a thickness of 0.5 mm. When the surface roughness (Ra) of both surfaces was measured with respect to the obtained glass plate, the value was 0.2 nm. The surface roughness (Ra) is a value measured by a method based on JIS B0601: 2001.

Furthermore, using EVA (thickness 25 μm), the glass plate and a resin plate made of PET (thickness 100 μm, surface roughness Ra 5 nm on both sides) were bonded with a laminator to prepare a composite substrate.

Sample No. listed in Table 1 After preparing glass raw materials so that the glass compositions described in 5 and 11 were obtained, the obtained glass batch was put into a continuous kiln and melted at a temperature of 1450 to 1600 ° C. Subsequently, the obtained molten glass was molded by an overflow down draw method to obtain a glass plate having a thickness of 0.5 mm. When the surface roughness (Ra) of both surfaces was measured with respect to the obtained glass plate, the value was 0.2 nm. The surface roughness (Ra) is a value measured by a method based on JIS B0601: 2001.

Furthermore, after applying a UV curable resin to the glass plate, a PET resin plate (thickness 100 μm, surface roughness Ra 1.0 μm on both sides) was stacked, and then UV irradiation was performed to prepare a composite substrate.

Claims (19)

A composite substrate in which a glass plate and a resin plate are bonded together,
A composite substrate, wherein the refractive index nd of the glass plate is 1.55 or more and 2.3 or less, and the refractive index nd of the resin plate is 1.55 or more and 2.3 or less. The glass plate has a glass composition of mol%, SiO ₂ 10-70%, B ₂ O ₃ 0-10%, SrO + BaO + La ₂ O ₃ + Nb ₂ O ₅ 0.1-60%, La ₂ O ₃ 0-35. %, Li ₂ O + Na ₂ O + K ₂ O 0-15%, the molar ratio (MgO + CaO + SrO + BaO) / (La ₂ O ₃ + Nb ₂ O ₅ + BaO + TiO ₂ + ZrO ₂ ) is 0.1 to 4, and the strain point is 600 2. The composite substrate according to claim 1, wherein the composite substrate has a refractive index nd of 1.55 to 2.3 at a temperature not lower than ° C. 3. The composite substrate according to claim 1, wherein the glass plate is made of glass having a liquidus temperature of 1250 ° C. or lower. The composite substrate according to any one of claims 1 to 3, wherein the glass plate is made of glass having a liquidus viscosity of 10 ^3.5 dPa · s or more. 5. The composite substrate according to claim 1, wherein the glass plate is formed by an overflow down draw method. The composite substrate according to any one of claims 1 to 5, wherein the surface roughness Ra of at least one surface of the glass plate is 10 nm or less. The composite substrate according to any one of claims 1 to 6, wherein the thickness of the glass plate is 2.0 mm or less. The composite substrate according to any one of claims 1 to 7, wherein the glass plate is made of glass having a density of 4.0 g / cm ³ or less. The composite substrate according to any one of claims 1 to 8, wherein the glass plate has a width of 100 mm or more and a length of 100 mm or more. The resin plate is made of any one of polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylonitrile copolymer, polyester, polyamide, polyimide, polyurethane, epoxy resin, polycarbonate, and acrylic. The composite substrate according to any one of the above. The composite substrate according to any one of claims 1 to 10, wherein an uneven structure is formed on at least one surface of the resin plate. The composite substrate according to any one of claims 1 to 11, wherein the surface roughness Ra of at least one surface of the resin plate is 0.5 nm or more. 13. The composite substrate according to claim 1, wherein the resin plate has a thickness of 0.01 to 3 mm. The composite substrate according to any one of claims 1 to 13, wherein an adhesive layer is provided between the glass plate and the resin plate, and the thickness of the adhesive layer is 100 µm or less. 15. The composite substrate according to claim 1, wherein a value of (refractive index nd of resin plate) − (refractive index nd of glass plate) is 0.001 to 0.1. The composite substrate according to any one of claims 1 to 15, wherein a haze value of the composite substrate is 5% or more. The composite substrate according to any one of claims 1 to 16, wherein the composite substrate is used for an illumination device. The composite substrate according to any one of claims 1 to 16, wherein the composite substrate is used for organic EL lighting. The composite substrate according to any one of claims 1 to 16, wherein the composite substrate is used for an organic EL display.